Absolute zero
3 marks · NormalA sample of gas is heated from -15 °C to 65 °C at constant volume. The initial pressure is 80 kPa.
Calculate the final pressure of the gas in kPa. Show all your steps and give your answer to 2 significant figures.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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110 kPa (±1)
Also accept: 109.6 kPa; 110 kPa
Common mistakes: Not converting °C to K; using the wrong formula.
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Converts both temperatures to Kelvin correctly.
M1 · 1 mark · Uses relationship correctly and rearranges for final pressure. (follow-through)
A1 · 1 mark · Correct final answer in kPa to two significant figures. (follow-through)
Worked solution
Initial temperature: T1 = -15 °C = 258 K
Final temperature: T2 = 65 °C = 338 K
Rearrange:
To two significant figures: 110 kPa